Radiotelegraphy.



E GIRARDEAU'& 1. BETHENOD.

RADIOTELEGRAPHY.

APPLICATION HLED JULY 26.1916.

1 345,702 Patented Nov. 6, 191?.

a 2 SHEETSSHEET 1.

I may dd f v v E. GiRARDEAU 431 J. BETHENOD.

HADIOTELEGRAPHY.

APPLICATION FILED JULY 26,1915.

Patented NO 6, 1917.

2 SHEETSSHEET 2. D H DG EMILE GIRARDEAU JOSEPH BETHEN 01), OF PARIS, CE.

RADIOTELEG RAPHY.

Specification of Letters Patent.

Application filed July 26, 1916. Serial No. 111,446. i

To all whom it may concern:

Be it known that we, EMILE GIRARDEA'U and .losnrii BETHENOD, both citizens of the French Republic, residing at 10 Rue Auber,

aris, in the Republic of France, have invented certain new and useful Improvements in Radiotelegraphy, of which the following is a specification.

This invention relates to the construction of multiple spark gaps, suchas are used for the production of oscillations by impulse in radio-telegraphy.

rofessor Wien was the first to show in 1906, that in order to bring about excitation by impulse of an oscillating, circuit it is advisable to use multiple spark gaps with very close metallic electrodes and a number of spark gaps proportioned to the tension brought into play. The impulse effect being in general the more accentuated according as the partial smaller, the great importance of reducing them as far as possible is evident, in View of the distinctness of the phenomenon and of the output.

arious methods have been suggested and used for the construction of such spark gaps, but those hitherto laid down generally lead to excessive heating, either in consequence of the discharge of the sparks in a closed vessel or in consequence of the shape of the electrodes, which is not favorable to the continual displacement of the sparks on the surface of the electrodes.

The method of construction forming the subject of the present invention greatly facilitates the cooling, at the same time considerably simplifying the construction itself.

Figure 1, annexed to this specification, shows a' first example of the application thereof. In this figure A is a plain or hol lOW cylinder of hard metal, on which are threaded rings of insulating material B;

on the latter the electrodes properlyso called fit with gentle friction, and a mica washer of very accurately gaged thickness, is arranged bctwcen two consecutive rings B; and finally the electrodes C are constituted in the form of disks comprising a hub E sparking distances are and a double swelling F, the axial thickness of the hub E and I of which is equal to that of the ring B. In this Way the sparking distance between two consecutive electrodes is equal to the gaged thickness of the Washers D, and the spark discharges between the swellings F opposite the tWo consecutive electrodes, the external diameter of the wash.- ers D being sufliciently .great to prevent any sparking between two adjacent hubs. As the adjustment of thevarious parts is easy, and may be effected with very great precision, it being assumed that, one is only concerned with turned parts, the exact parallelism of the electrodes is insured, and the spark runs constantly over the active surface of the electrodes.

In order to insure trodes, which is indispensable to the satisfactory working of the spark gap, the latter terminate in vanes G; in addition to which they are pierced with several holes H, thanks to which the air inclosed between two electrodes can circulate and be continually renewed. 1 I

The ribs G serve at the same time for the collection of current, suitable terminals 0 and O enabling a larger or smaller number of spark gaps to be brought into operation.

For very powerful-stations the spark gap that We have ust described may of course be utilized, but-it is advisable to insure by mechanical means the compulsory rotation of the spark, for the slightest, stoppage of the latter may then cause ldical consumption of the electrodes, which is exceedingly harmful to the satisfactory workingof the spark gap. T t is to this end that the method of construc tion represented by way of example in Fig. 2

- corresponds.

In this spark gap half the electrodes are fixed and the other half are movable, A

metallic frame L supports the fixed elec-.

trodes C. They are in the form of rims and carry two swellings F, which constitute the active surfaces. These electrodes are provided with vanes G to insure the cooling thereof, and are insulated from one another by washers of mica (or 'other insulating ma-- Patented Nov. 6, 191 7.

the cooling of the elec- I terial) indicated They are then pressed against. one by any suitable locking device.

The mounting of the movable electrodes is exactly the same as that snown in Fig. l. The movable electrodes are supported by a shaft A, on which are fitted the insulating rings B. On the latter are fiXCCl With gentle friction the electrodes (l, which are insulated from one another by inica Washers l), Up to this point, therefore the construction absolutely identical with that of Fig. 1. The outer part of the electrodes is slightly lnOlill" ficd. It carries two s ellings F which are placed opposite the swellings F oft the moi able electrodes.

The shaft A may be rotated by a system of gearing; R controlled by a pulley ll, which makes the whole system rotate about the axis X X and at the same time makes the shaft A rotate about the axis Y Y. In this Way the points of discharge of the sparks are continually renewed and consequently the cooling; of the electrodes is etl'ectually secured.

Fig. shows the arrangement. in plan, in order to indicate better the relative positions of the electrodes and their rotary movements.

Modifications of detail inay of cours be made in the method of construction forming the subject of this patent without altering the essential principle of the invention. Thus the shape of the electrodes may be modified. The number of electrodes is of course on tionah and may be anything Whatever.

What We claim and desire to se ure by Le ters Patent in the United States 'lSZ- 1. In an electric spar the conibination of a plurality of movable electro .es provided With registerin appa atus niit of the flow of air currents through t entire set of electrodes on a line parallel o the axis thereof.

2. An electric spark gap comprising a plurality of dislts forming electrodes "pro- Vided with a plurality of transverse aper tures to permit of the flow of air through the entire set oi disks parallel to the axis thereof, and inc-ans to allow of air circulating through and between adjacent disks.

at D ot' gaged thickness. another 3. In an electric spark gap, a circular electrode, having a. circular reduced porti i centric with its axis. and r ea' of the transverse passage of tliro reduced portion of the electrode.

4. "in an electric spark an electrode comprising a circular boss, a circular ring o1 bulbous cross section, means connecting said boss and ring; an annular space :orzned in the external periphery-ct and extending to near the center o1 said bu bous "part means to allow of air circulating axially of said connecting means. 7 i

in an electric sparlt gap the conihination of a plurality of fixed electro l s plurality o'l rotatable electrodes pro With radiating vanes and means in the rotatable electrodes adjacent the runes to no flow of air through the enti re of 1 ill} electrodes.

6. In an electric spark gap, the co 'ioination of a plurality of lifted elect plu rality of rotatable e t odes. n tatc aid latter electrodes about the axis of the fixed electrodes and n1 *ans within the rotatable electrodes to -oern'iit oi the lieu of air through the entire set of rotatable electrodes.

T. In an electric spark, the co )inati :1 8t) of a plurality of fixed electrodes, a plurality of movable electrodes, means to rotate said latter electrodes about the aXis of the fixed electrodes. means to rotate said notable electrodes on their own axis and means With- 35 in the rotatable electrodes to permit of air circulating tl'u'ough the entire set of rotatable electrodes.

8. In an electric spark gap, the COllllfllIlfition of a plurality of fixed electrodes. phirality of movable electrodes, means to rotate said movable electrodes simultaneously about two axes and means to permit of air circulating axially through the entire set of retatable electrodes.

9. ln an electric spafi'gap, the tion ot a plurality of fixed electrodesplurality of inoi'able electrodes. means to rotate said movable electrodes simultaneous: about two axes and means projecting from 111i rotatable electrodes to facilitate heat radiations therefrom.

10. la an electric snarl; can, ti-ou a plurality of ele raliry of moraine electrodes I a circular boss, a circular r cross section, means connecti and circular ring, an annular spac'. in the exterior of said bulbous tending to near the center of 1 part and means to rotate l. trodes simultaneously ahout tr.

11. la an electric snark are tion of stationary electr c" ulu axe 3 a '7 e in. in an eiecnicspi n.

a 2 tion of station electrodes s paced. a 'iart annular space es stag- 12E .e interior e eon-aces and ee-wee 3 means to rotate said rotatable electrodes simultaneously. on theirgown axis and about the axis of the fixed elentrodes. 13. an. electric spark gap, the combination of; fixed "electrodes, rotatable electrodesa nd suppei ts-for both said fixed and rotatable'eieetredes} gearing between the reatable' eleetl ed'esend fixed electrodes, means to support theirq'tetetile electrodes from the support of the fixed electrodes and means 1 to rotate said rotatable electrodes.

In testimony whereef We eflix our signetnres in presence of two Witnesses.

EMILE GIRARDEAU. JOSEPH .BETHENOD. /"litnessesz TRACY LAY, EUGENE VERTARIN. 

